Why does ROM Manager ask for account permissions?
Web Connect only needs to access your Google account to connect it to your google account. It can't any private data or passwords.

Troubleshooting:
Droid users: Stuck at the "M" logo? Flash an alternate recovery and flash back to ClockworkMod.
HTC Users: Flash recovery not working? Try fastbooting a recovery on.
Droid X/2/Pro Users: You must run the Bootstrap application first to use ROM Manager.
Samsung users: You must flash a Clockwork compatible kernel first (see XDA forums)